YANGON, Myanmar -- Two Buddhist monks who were among scores seriously burned during a 2012 police crackdown on protesters campaigning against a Chinese-backed copper mine have filed a lawsuit against Myanmar's home affairs minister and police chief, one of the monks said Monday.

More than 100 monks suffered serious burns from smoke bombs that reportedly contained white phosphorous when police dispersed the protesters at the Letpadaung copper mine in northwestern Myanmar.

"We are suing the government not out of grudge or for personal gains, but because we want justice," 42-year-old monk U Withoda said at a news conference in Yangon.

U Withoda also called on the government to make a public apology for the use of phosphorous bombs during the crackdown and to resolve the grievances of land grab victims. The Letpadaung mine has been a focal point of land rights disputes in recent years.

Aung Thein, a prominent lawyer who is assisting the two monks, said that since no one has taken responsibility for the injuries sustained during the crackdown, U Withoda and fellow monk U Tikha Nyana filed a lawsuit last week against the home minister, Maj. Gen. Ko Ko, and the national police chief, Zaw Win.

U Tikha Nyana suffered burns over about 60 per cent of his body during the crackdown, while U Withoda's burns were not as severe.

Aung Thein said he was ready to help if other monks who were burned during the crackdown want to join the lawsuit.

The human right group Justice Trust, which works to advance rule of law in Myanmar and is supporting the monks, said in a statement that the lawsuit was launched for the ordering of what it called an illegal police action.

It said that 57 of the injured monks suffered serious burns requiring long-term medical care.

The protest in November 2012 drew international attention. This past December, a villager was shot dead during a confrontation as police and Chinese workers erected a fence on land that villagers claimed was theirs.

The Letpadaung mine is a joint venture between a Myanmar military-controlled holding company and China's Wanbao Mining Copper Ltd., a unit of weapons manufacturer China North Industries Corp.